This article provides a comprehensive overview of why and how companies are valued, covering key methods such as market capitalization, discounted cash flow (DCF), asset-based approaches, and comparative analysis. It explains the importance of valuation for investment decisions, mergers and acquisitions, financial reporting, and strategic planning. With clear examples and insights into risk assessment and market trends, this guide is essential for investors, business owners, analysts, and finance students seeking to understand the principles and practices of business valuation.